WEST LAFAYETTE, Ind. - A lone gunman walked into a basement classroom at Purdue University on Tuesday, shot and killed one person, then calmly walked outside and turned himself in, police said.

Purdue Police Chief John Cox said the suspect appeared to have targeted the male victim in the classroom of the Electrical Engineering Building about noon and didn't attack anyone else. The school newspaper reported that the victim was a teaching assistant.

"The individual entered the facility and took the actions that he took, and then immediately left the facility without any other interaction that we're aware of," Cox told reporters.

The suspect walked outside - unarmed - and turned himself in to a West Lafayette police officer. Cox said the suspect did not resist arrest but was not otherwise cooperating with police.

Cox and Purdue Provost Timothy Sands confirmed the fatality at a news conference. The names of the suspect and the victim were not immediately available.

The Purdue Exponent, the school newspaper, reports that the victim was a teaching assistant, but did not elaborate on its source or how the shooting occurred.

The initial campus-wide lockdown was partially lifted after about two hours, although police continued to search the engineering building.

"The campus is safe, it has been cleared," Sands said. "We're encouraging students to continue about their usual business on the rest of the campus except for the Electrical Engineering Building."

University President Mitch Daniels is traveling in Colombia but is being updated on the situation, Sands said.

In June he will become president of Virginia Tech, site of the April 2007 massacre that left 32 people and the student gunman dead.

Ben Snyder, a senior from Fort Wayne, Ind., told the Journal & Courier that he heard two shots followed by shouts of "get down, get down!" Snyder also said he saw at least one person being taken away in handcuffs by police and "a guy with blood on his hands."

The newspaper said one male was brought outside the Electrical Engineering Building with his hands behind his back.

Erica Ambrose, a senior in the School of Agriculture, was attending class in the building when the shooting occurred, the Purdue Exponent reports.

"We heard shouting downstairs and it sounded like people were running through the hallways, just yelling at each other," she told the newspaper.